Micromirrors are described in the related art which have two axes of rotation that are perpendicular to each other, so that light can be deflected not only in one plane, but in two planes. For example, presently such micromirrors are contemplated for head-up displays in the automotive sector, but also for other applications such as image projectors and 2-D scanners.
To permit the mobility of a micromirror in two planes, the micromirror is usually doubly suspended cardanically on torsion springs. In so doing, for example, the micromirror may be surrounded by an inner cardan frame and joined to this inner cardan frame via a pair of aligned torsion joints. In turn, the inner cardan frame is joined via aligned torsion joints to an outer cardan frame. However, the cardanic suspension has the disadvantage that it is relatively complicated in design and actuation, and in addition, also has disadvantages with respect to the dynamic properties of the micromirror.
Alternatively, two individual micromirrors may also be mounted in tandem in freely suspended manner with, in each case, only one axis of rotation, perpendicular to each other in the optical path. In this case, the suspension mount or the torsion joint lies in a plane different from the mirror plane. The individual mirror elements may be side-by-side mounted virtually without gap. However, this has the disadvantage that the optical adjustment of the mirrors in the optical path is relatively complicated. For example, an imprecise mounting results if the micromirrors are only inserted or put on. Their position is then often indefinite, and specially adapted tools are needed to align the micromirrors exactly.